The Arabidopsis thaliana JASMONATE INSENSITIVE 1 gene is required for suppression of salicylic acid-dependent defenses during infection by Pseudomonas syringae

Mol Plant Microbe Interact. 2006 Jul;19(7):789-800. doi: 10.1094/MPMI-19-0789.

Abstract

Many plant pathogens suppress antimicrobial defenses using virulence factors that modulate endogenous host defenses. The Pseudomonas syringae phytotoxin coronatine (COR) is believed to promote virulence by acting as a jasmonate analog, because COR-insensitive 1 (coil) Arabidopsis thaliana and tomato mutants are impaired in jasmonate signaling and exhibit reduced susceptibility to P. syringae. To further investigate the role of jasmonate signaling in disease development, we analyzed several jasmonate-insensitive A. thaliana mutants for susceptibility to P. syringae pv. tomato strain DC3000 and sensitivity to COR. Jasmonate-insensitive 1 (jin1) mutants exhibit both reduced susceptibility to P. syringae pv. tomato DC3000 and reduced sensitivity to COR, whereas jasmonate-resistant 1 (jar1) plants exhibit wild-type responses to both COR and P. syringae pv. tomato DC3000. A jin1 jar1 double mutant does not exhibit enhanced jasmonate insensitivity, suggesting that JIN1 functions downstream of jasmonic acid-amino acid conjugates synthesized by JAR1. Reduced disease susceptibility in jin1 mutants is correlated with elevated expression of pathogenesis-related 1 (PR-1) and is dependent on accumulation of salicylic acid (SA). We also show that JIN1 is required for normal P. syringae pv. tomato DC3000 symptom development through an SA-independent mechanism. Thus, P. syringae pv. tomato DC3000 appears to utilize COR to manipulate JIN1-dependent jasmonate signaling both to suppress SA-mediated defenses and to promote symptom development.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acids / pharmacology
  • Arabidopsis / drug effects
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism*
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / genetics*
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / metabolism*
  • Cyclopentanes / metabolism
  • Gene Expression Regulation, Plant
  • Indenes / pharmacology
  • Mutation
  • Nucleotidyltransferases / genetics
  • Nucleotidyltransferases / metabolism
  • Oxylipins
  • Plant Diseases / genetics
  • Plant Diseases / microbiology*
  • Plant Roots / drug effects
  • Plant Roots / growth & development
  • Plant Roots / metabolism
  • Pseudomonas syringae / physiology*
  • Salicylic Acid / metabolism*
  • Signal Transduction

Substances

  • Amino Acids
  • Arabidopsis Proteins
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Cyclopentanes
  • Indenes
  • MYC2 protein, Arabidopsis
  • Oxylipins
  • coronatine
  • jasmonic acid
  • JAR1 protein, Arabidopsis
  • Nucleotidyltransferases
  • Salicylic Acid